Gear for holding a physiological sensor

ABSTRACT

A wearable gear ( 100 ) for holding a physiological sensor for monitoring a subject, such as a pulse oximeter. Said wearable gear being configured to automatically adjust the maximal length such that the predefined tension is obtained regardless of the size of the body part of the subject. The wearable gear comprises a tensioning element ( 102 ) having a maximal length, a holding unit for holding the physiological sensor, the wearable gear further comprises a tension mechanism for tensioning the tensioning element to a predefined tension when at least partially around a body part of the subject, wherein the tension mechanism comprises i) a first part comprising a resilient material, and ii) a second part comprising a non-resilient material, and wherein the first part and the second part mechanically cooperate with each other to automatically adjust the maximal length such that the predefined tension is obtained regardless of the size of the body part.

FIELD OF THE INVENTION

The invention relates to a wearable gear for holding a physiologicalsensor for monitoring a subject, the wearable gear comprising atensioning element having a maximal length, and a holding unit forholding the physiological sensor.

The invention further relates to a monitoring device for monitoring avital sign of a subject, the monitoring device comprising a tensioningelement having a maximal length, and a physiological sensor forreceiving vital sign parameter data.

The invention further relates to a method for holding a physiologicalsensor for monitoring a subject, said method comprising the steps ofproviding a wearable gear comprising a tensioning element having amaximal length, and coupling the wearable gear to a holding unit forholding the physiological sensor.

BACKGROUND OF THE INVENTION

Pulse oximetry is a technique for assessing the oxygen (O₂) saturationof blood in the animal or human body in a non-invasive manner. Since itsintroduction in the clinic, pulse oximetry has become a standard of carein various clinical settings. A pulse oximeter probe is usually appliedto a fingertip. Red and infrared light is transmitted into the tissue bytwo light-emitting diodes (LEDs), and the scattered light is recorded bya photodiode at the other side of the tissue. The cardiac-inducedpulsations in the blood volume manifest themselves as pulsations in thedetected light intensity. The oxygen saturation is derived from theratio of pulse amplitudes in the red and infrared light intensity, wherethe relationship results from a difference in color of oxygen-bound andoxygen-unbound hemoglobin.

Apart from the fingertip, there are various other body locations thatmay be used to measure the oxygen saturation (SpO2) of a person, such asthe ear lobe, the ear concha, the forehead, the alar wing, the toes, thehand, and the foot. Similar to the above disclosure, two wavelengths oflight are emitted through the body part and the scattered light isdetected via a photodetector. The changing absorbance at each of thewavelengths, allowing determination of the absorbance due to the pulsingarterial blood alone.

The forehead is a special location of the body for SpO2 measurement, asit is the only commonly-used location in reflection geometry, in whichthe light source(s) and detector are facing the same way, and onlyback-scattered light is detectable. For this location, the contactpressure of the pulse oximeter probe is of crucial importance for acorrect measurement of the oxygen saturation value. If the contactpressure is too low, venous pooling and venous pulsation can causefalsely low SpO2 readings. If the contact pressure is too high, itbecomes uncomfortable, or, in extreme cases, the arteries are collapsedsuch that no pulsations can be recorded at all.

In low-resource settings (e.g. rural areas) pulse oximetry is scarcelyused. It has nonetheless been revealed that for diagnosing specificdiseases (e.g. pneumonia), supplementing the diagnostic profile withpulse oximetry may provide a valuable advantage, which could help earlydiagnostic of some specific diseases with the advantage of reducingmortality. For example, the World Health Organization (WHO) took thedecision to adapt its guidelines of diagnosing pneumonia, wherein theseinclude the recommendation of using SpO2 measurement, in addition to therespiration rate.

A headband for receiving an oximetry sensor is known from U.S. Pat. No.7,698,909 B2. Said headband comprises a low stretch segment sized to fitaround a wearer's head; and an elastic segment being smaller than thelow stretch segment. The elastic segment has a free end and an attachedend, where the elastic segment is attached at its attached end with thelow stretch segment, and the free end of the elastic segment isconfigured to form a closed loop with the low stretch segment around awearer's head.

It is a drawback of known forehead pulse oximeter that a fluentplacement of the headband requires practice such that closure of theheadband at the correct tension is achieved. It is a further drawback ofknown forehead pulse oximeter that they cannot be used for users ofdifferent head sizes while warranting the proper contact pressure of apulse oximeter probe on the forehead.

SUMMARY OF THE INVENTION

It is an object of the invention to provide a wearable gear the kind setforth in the opening paragraph which is configured for applying aphysiological sensor at a proper pressure on the forehead of a subject,while simultaneously being adaptable to number of head sizes such thatonly one wearable gear can be used by multiple users (or patients),thereby providing ease of physiological parameter(s) measurement, suchas oxygen saturation measurement.

Preferably, the wearable gear is optimized to be suitable for childrenbetween the age of zero (0) to five (5) years old.

According to a first aspect of the invention, this object is realized bya wearable gear of the kind set forth in the opening paragraph whichfurther comprises a tension mechanism for tensioning the tensioningelement to a predefined tension when at least partially around a bodypart of the subject, wherein the tension mechanism comprises i) a firstpart comprising a resilient material, and ii) a second part comprising anon-resilient material, and wherein the first part and the second partmechanically cooperate with each other to automatically adjust themaximal length such that the predefined tension is obtained regardlessof the size of the body part. Preferably, said predefined tensioncorresponds, when in use, to a pressure applied by the physiologicalsensor on the body part within a predefined pressure range.

It is an advantage of the wearable gear according to the invention toprovide the contact pressure of the physiological sensor on the bodypart (for instance the forehead, the wrist, the arm) within apreferential pressure range while said wearable gear is easy to use forall type of users (and/or health workers and/or care givers (formal andinformal)).

Additionally, it is a further advantage of the wearable gear accordingto this invention to simultaneously being suitable to fit on any bodypart sizes while automatically providing the contact pressure of thephysiological sensor on said body part within said preferential pressurerange. In other words, the wearable gear according to the invention canextend over a large range of body part sizes without an excessiveincreased of the tension in the wearable gear, therefore enabling thecontact pressure to remain within the preferential pressure range.

It is a further advantage of the wearable gear according to theinvention that the physiological sensor is held in place by the wearablegear without the need to adhesively attach said physiological sensor tothe subject's body part, and/or without requiring two or more personsfor its installation or adjustment around the subject's body part.

It is a further advantage of the wearable gear according to theinvention in that the proper tension of the wearable gear isautomatically reached, therefore enabling, when the holding unitcomprises a physiological sensor, a proper (an adequate, an optimal, asatisfactory) contact pressure of said physiological sensor on thesubject's body part regardless of a user's (and/or health worker and/orcare giver (formal and informal)) experience. As a result of theforegoing, adequate reading from the physiological sensor is enabled inall, or nearly all circumstances regardless of experience and/orpractice and/or prior training in positioning such physiological sensoron a body part.

As set forth above, an advantage of the wearable gear according to theinvention is that it enables a “one size fits all” wearable gearregardless of the subject's body part size, for instance the size of thesubject's head. Although not limited to children, the wearable gearaccording to the present invention (for instance a headband) isparticularly suitable for use with users of age group between 0(following birth) to 5 years old as the size of the body part (forinstance the head) is growing significantly and rapidly. As suchwearable gear is configured to automatically adjust its maximal lengthsuch that a predefined tension is reached, the wearable gear is suitablefor number of body part sizes (for instance head sizes) which enablesmultiple use with multiple users without the need to have differentwearable gear sizes for holding the physiological sensor.

A further advantage of the wearable gear according to the invention isthat the maintenance of the wearable gear is optimized for health careworkers in low resource settings and/or in secondary or tertiary careenvironments. By a “one size fits all” wearable gear, said health workerdoes not need to take care of a plurality of gears and/or physiologicalsensors, but only one that aims to ease the health worker daily job,especially within rural and/or remote regions characterized by limitedsupply of good and/or maintenance.

The holding unit according to the present invention is configured tohold the physiological sensor, for instance a pulse oximeter, areflective pulse oximeter, a blood pressure sensor, a blood volumesensor, a heart rate sensor, a temperature sensor, a respiratory sensor,a galvanic skin response sensor, an electrocardiogram sensor, anear-infrared spectroscopy sensor, a hemoglobin concentration sensor, anelectro encephalogram sensor, an accelerometer, an activity or posturesensor or any other sensors which may be influences by a pressureexerted by said sensor on a subject's body part, such as the forehead,the fingers, the toes, the harm, the chest.

A resilient material has resilient content (k), characterized in howstiff and/or strong said resilient material is (for instance, based onHooke's law when such resilient material is a spring, or an elastic). Assuch constant (k) is unique to a given material, the skilled in the artwill easily understand that number of resilient materials may be chosensuch that the wearable gear reaches, when in use, the predefined tension(or optimal, or preferable) as function of the size of the body part,such as the head. Such predefined tension, as it will be elucidatedhereunder, is proportional to the diameter of the head. Consequently,this embodiment ensures that the wearable gear is suitable toautomatically reach the predefined tension regardless off the subject'sbody part size, consequently allowing, when in use, the physiologicalsensor to exert a pressure within the preferable pressure range on saidsubject's body part (for instance the head), thereby enabling adequatereading of the vital sign by the physiological sensor (for instance apulse oximeter).

In a further embodiment, the resilient material comprises a spring or anelastic. Preferably, when comprising a spring, said spring is one of atorsion springs, a helical torsion spring or a clock spring. Thisarrangement is advantageous as it enables easy coupling between saidresilient material and the non-resilient material such that theadvantages of the wearable gear according to the present invention arereached.

In a yet further embodiment, the maximum length of the wearable gearcomprises a first portion and a second portion, wherein said firstportion and second portion are coupleable by a coupling element, saidcoupling element configured to connect said first portion and saidsecond portion such that the first portion and the second portion tomove relative to each other such that the predefined tension remainsstable when surrounding the body part once the predefined tension isreached. This arrangement is advantageous as it enables a cooperationbetween the tension mechanism and the remaining of the wearable gearsuch that the advantages set forth above are met while enabling an easypositioning of the wearable gear at least partially around the subject'sbody part while ensuring automatic adjustment such that the predefinedtension is reached.

In a yet further embodiment, the coupling element for coupling the firstand the second portion is further configured to enable the wearable gearto be held in place when at least partially surrounding the body partwhen the first portion and second portion are coupled to each other.This arrangement is advantageous as it enables the wearable gear to beclosed by the subject, or by any person, such as a family member, ahealth worker within a closed loop such that the wearable gear surrounds(in part or in full) the subject's body part at the predefined tension.

In an example, the tension mechanism of the wearable gear furthercomprises a rotating element rotatable around an axis, said rotatingelement being coupleable to the resilient material such that therotating element and the resilient material are engageable so as toshorten the maximal length. This arrangement is advantageous as itenables, among other things, manual incremental adjustment of thewearable gear to reach an optimal tension, therefore an optimal pressureonce following automatically reaching the predefined tension inaccordance with present invention.

In a further embodiment, the coupling element and the tension mechanismare congruent (coinciding exactly, or nearly exactly when superimposed).This arrangement is advantageous as it enables easy handling,installation and use of the wearable gear according to the presentinvention where one hardware feature may provide two different effectsin accordance with the present invention.

In a yet further embodiment, the wearable gear further comprises aposition indicator for indicating the appropriate placement of thewearable gear or the holding unit on or at least partially around thesubject's body part. This arrangement is advantageous as it enablesaccurate positioning of the wearable gear such that, when in use, thephysiological sensor is adequately located on the subject's body part soas to provide adequate reading therefrom. Such position indicator may bea mark, a light, a feedback signal or other means as it will be furtherelucidated hereunder, but in any event enables easy and optimalpositioning of said wearable gear at least partially around thesubject's body part by the subject or any other persons, or user such asa health worker.

In a yet further embodiment, the holding unit of the wearable gearcomprises the physiological sensor, such as a pulse oximeter, preferablya reflective pulse oximeter. This arrangement is advantageous as itenables easy handling of wearable gear, without the need of two or moreparts. Having a wearable gear according to the present inventioncomprising the wearable sensor limits considerably handling mistakes, ormisplacement of the wearable sensor within the holding unit, increasingthe robustness and ease of operation of such device.

In a yet further embodiment, the predefined tension enables a pressurerange between 0.667 kPa (5 mmHg) and 6.666 kPa (50 mmHg), preferablybetween 2.000 kPa (15 mmHg) and 3.333 kPa (25 mmHg) applied on the bodypart. In accordance with the present invention, “kPa” means kilopascaland “mmHg” means millimeter of mercury, both corresponding herein tounits of pressure. This arrangement is advantageous as it enablesoptimal reading from the physiological sensor, especially when saidphysiological sensor is a pulse oximeter for reading a vital sign fromthe subject's forehead. Said exerted pressure on the subject's bodypart, such as the forehead, should be, and should remain above thecentral venous pressure and below systolic pressure and preferably belowthe diastolic pressure; the latter determining the adequate pressurerange. It will be appreciated that, preferably, said pressure rangeshould be between 2.000 kPa (15 mmHg) and 3.333 kPa (25 mmHg) as it hasbeen demonstrated that said pressure is for all, or nearly all humans ofall groups of age, above the blood pressure in the venules and below thediastolic arterial pressure, even in newborn when children in an uprightposture.

In a yet further embodiment, the wearable gear is a headband to be wearat least partially around a head of the subject. This arrangement isadvantageous as it enables all advantages of the wearable gear accordingto the present invention for use with a physiological sensor, such as apulse oximeter, configured to be positioned on the subject's forehead,or at any locations suitable for proper reading of vital sign(s) fromsaid physiological sensor. Such headband is easy to manufacture, is easyto use by a lay person, or a healthcare worker such as to getinformation, for instance, oxygen level (or oxygen saturation) in thesubject's blood while enabling all of the advantages hereby mentioned.

According to a second aspect of the invention, the object set forthabove is realized by a monitoring device of the kind set forth in theopening paragraphs, which further comprises a tension mechanism fortensioning the tensioning element to a predefined tension when at leastpartially around a body part of the subject, wherein the tensionmechanism comprises i) a first part comprising a resilient material, andii) a second part comprising a non-resilient material, and wherein thefirst part and the second part mechanically cooperate with each other toautomatically adjust the maximal length such that the predefined tensionis obtained regardless of the size of the body part. Preferably, saidpredefined tension is corresponding, when in use, to a pressure rangeapplied by the physiological sensor on the body part.

It is an advantage of the monitoring device according to the inventionto allow non-invasive continuous or semi-continuous monitoring of asubject by means of a physiological sensor, for instance a pulseoximeter, a blood pressure sensor, a blood volume sensor, a temperaturesensor, a respiratory sensor, a galvanic skin response sensor, anelectrocardiogram sensor, a near-infrared spectroscopy sensor, ahemoglobin concentration sensor, an electro encephalogram sensor, anaccelerometer, an activity or posture sensor, or any other sensor whichmay be influences by a pressure exerted by said sensor on a subject'sbody part, such as the forehead, the fingers, the toes, the harm, thechest.

It is a further advantage of the monitoring device according to thepresent invention that the target contact pressure is reached, at leastpartially automatically, preferably fully automatically without the needfor active adjustment of the contact pressure by the subject or on thesubject's behalf.

A further advantage of the monitoring device according to the presentinvention is that the physiological sensor is integrated into thewearable gear (for instance a headband) such that only one element isneeded to be apply onto the subject in order to prepare the device forthe physiological measurement by the physiological sensor, therebyalleviating the need for two or more elements (such a physiologicalsensor and a carrier), thereby increasing robustness of the monitoringdevice.

In an embodiment, the physiological sensor is a pulse oximeter,preferably a reflective pulse oximeter. This arrangement is advantageousas it enables measurement of the oxygen level (or oxygen saturation) inthe subject's blood at different location, even when the pulse oximeterlight signal cannot cross the blood vessel, for instance if positionedon the subject's forehead, or other body part which do not enablereceipt of said emitted light signal from another side of the emitter.

In a yet further embodiment, the physiological sensor of the monitoringdevice is coupled to a pressure sensor, said pressure sensor configuredto generate a pressure signal indicative of the pressure exercised bythe physiological sensor on the body part. This arrangement isadvantageous as it enables at least some components of the monitoringdevice to cooperate and/or to move relative to each other and/or to bemoved relative to each other based on such pressure signal. Withoutlimitation to the disclosure herein, the skilled in the art willcontemplate number of advantages of the generation and the successiveoutput of a pressure signal in accordance to this embodiment, andfurther elucidated hereunder.

In a yet further embodiment, the tension mechanism of the monitoringdevice is configured to cease tensioning of the monitoring device whenthe pressure signal reaches a predefined threshold indicative of thepredefined pressure or pressure range. This arrangement is advantageousas it enable an automatic adjustment of the monitoring device at atension and/or at a pressure known to the subject. Additionally oralternatively, such embodiment is advantageous as it enables a failsafemechanism so as to ensure that the predefined tension is automaticallyreached from the means and elements herein described. Additionally oralternatively, this embodiment enables easy robotization of the tensionmechanism.

In a yet further embodiment, wherein the predefined tension enables apressure range between 0.667 kPa (5 mmHg) and 6.666 kPa (50 mmHg),preferably between 2.000 kPa (15 mmHg) and 3.333 kPa (25 mmHg) appliedon the body part. This arrangement is advantageous for analogous reasonsas mentioned for the wearable gear according to the present invention.In essence, said embodiment enables optimal reading from thephysiological sensor, especially when said physiological sensor is apulse oximeter for reading a vital sign from the subject's forehead.Said exerted pressure on the subject's body part, such as the forehead,should be, and should remain above the central venous pressure and belowsystolic pressure and preferably below the diastolic pressure; thelatter determining the adequate pressure range. It will be appreciatedthat, preferably, said pressure range should be between 2.000 kPa (15mmHg) and 3.333 kPa (25 mmHg) as it has been demonstrated that saidpressure is for all, or nearly all humans of all groups of age, abovethe blood pressure in the venules and below the diastolic arterialpressure, even in newborn when children in an upright posture.

In a yet further embodiment, the monitoring device further comprises afeedback unit for providing a feedback as to the positioning of thephysiological sensor relative to a position of interest of the subject.This arrangement is advantageous as it enables the subject, or a healthworker, or a care giver (formal or informal) to confirm or reasonablyconfirm that the predefined tension is reached, or on its way to bereached, thereby enabling control and/or adequate determination that themonitoring system according to the invention is ready to initiatemonitoring of the vital sign (such as oxygen saturation) via thephysiological sensor. Additionally or alternatively, this embodimentenables the subject, or any other person to know with relative precisionthe pressure exercised by the physiological sensor on the body part suchas to trigger a possible response (such as to take a measure, tomanually incrementally increase or decrease the tension of themonitoring device) from the subject, the health worker, the care giveror any other person in the subject's vicinity. Such feedback may takenumber of forms, as it will be elucidated hereunder, but withoutlimitation an alarm signal (for instance a visual signal, an audiosignal), said signal being indicative of the force sensed by the sensoror any other pressure signal that will be foreseen by the skilled in theart.

According to a third aspect of the invention, the object set forth aboveis realized by a method of the kind set forth in the opening paragraphwhich further comprises the steps of i) providing a tension mechanismfor tensioning the tensioning element to a predefined tension when atleast partially around a body part of the subject wherein the tensionmechanism comprises i) a first part comprising a resilient material, andii) a second part comprising a non-resilient material, and ii) providingthe first part and the second part mechanically cooperate with eachother to automatically adjust the maximal length such that thepredefined tension is obtained regardless of the size of the body part.

The advantages of the method according to the present invention areanalogous to the corresponding advantages for the wearable gear and/orthe monitoring device according to the present invention.

These and other aspects of the invention are apparent from and will beelucidated with reference to the embodiments described hereinafter.

It will be appreciated by those skilled in the art that two or more ofthe above-mentioned options, implementations, and/or aspects of theinvention may be combined in any way deemed useful.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other aspects of the applicator device, the system and themethod according to the invention will be further elucidated anddescribed with reference to the drawing, in which:

FIG. 1 is a schematic representation of an embodiment of a wearable gearaccording to the present invention.

FIG. 2 is a schematic representation of an embodiment of a wearable gearaccording to the present invention when comprising a physiologicalsensor and a position indicator.

FIG. 3 is a schematic representation of an alternative embodiment of awearable gear according to the present invention when comprising aphysiological sensor and a position indicator.

FIG. 4 is a graphical representation of the tangential force (in Newton(N)) in a wearable gear surrounding a body part relative to thecircumference (in centimeter (cm)) of the body part.

FIG. 5 is a schematic representation of a tensioning element coupled toa tension mechanism according to an embodiment of the present invention.

FIG. 6 is a schematic representation of a tensioning element coupled toa tension mechanism according to an embodiment of the present invention.

FIG. 7 is a schematic representation of a tensioning element coupled toa tension mechanism according to an embodiment of the present invention.

FIG. 8 is a schematic representation of a tensioning element coupled toa tension mechanism according to an embodiment of the present invention.

FIG. 9 is a schematic representation of a tensioning element coupled toa tension mechanism according to an embodiment of the present invention.

FIG. 10 is a schematic representation of a tensioning element coupled toa tension mechanism according to an embodiment of the present invention.

FIG. 11 is a schematic representation of a tensioning element coupled toa tension mechanism according to an embodiment of the present invention.

FIG. 12 is a schematic representation of a method according to thepresent invention.

DETAILED DESCRIPTION OF EMBODIMENTS

Certain embodiments will now be described in greater detail withreference to the accompanying drawings. In the following description,like drawing reference numerals are used for like elements, even indifferent drawings. The matters defined in the description, such asdetailed construction and elements, are provided to assist in acomprehensive understanding of the exemplary embodiments. Also, wellknown functions or constructions are not described in detail since theywould obscure the embodiments with unnecessary detail. Moreover,expressions such as “at least one of”, when preceding a list ofelements, modify the entire list of elements and do not modify theindividual elements of the list.

FIG. 1 is a schematic representation of an embodiment of a wearable gear100 according to the present invention. Said wearable gear 100 comprisesa holding unit 101, for instance a pocket, a pouch, for holding aphysiological sensor (such as a pulse oximeter). Alternatively, saidholding unit may comprise a connector to couple the physiological sensorto the wearable gear 100, such as a magnet, a clip, a clamp, an adhesivelayer or any other means that would be known to the skilled in the art.

The wearable gear 100 further comprises a tensioning element 102configured to tension the wearable gear 100 around the body part. In anexemplary embodiment, said tensioning element 102 is the warble gear100. Said tensioning element 102 is configured to be extensible suchthat it provokes an increase or a decrease of the maximal length of thewearable gear 100. As it will be elucidated hereunder, number of meanshave been foreseen by the inventors for such tension mechanisms, wherethe description of the present embodiment should not be limited to thedisclosed means.

As depicted in FIG. 1, the tensioning element 102 is located between afirst end 103 a and a second end 103 b of a non-flexible orsemi-flexible sleeve 104 such that the wearable gear 100 forms a closeloop that can surround a body part of a subject, for instance the head,the arm, the chest, the wrist. Alternatively, the tensioning element 102may comprise the whole length of the wearable gear 100; consequently thelength of the tensioning element 102 is associated with the length ofthe wearable gear 100.

It is to be noted that the tensioning element 102 and the sleeve 104 maybe arranged such that they form an open loop which would partiallysurround the subject's body part. In such embodiment (not shown), thetensioning element 102 may be positioned to cooperate only with thefirst end 103 a, alternatively only with the second end 103 b,alternatively to be located between the first end 103 a and the secondend 103 b. In this arrangement, that both first and second ends 103 a,103 b are configured to cooperate with the body part such that theeffect set forth herein are achieved; in other words such that thetension mechanism 102 is automatically adjusts the maximal length of thewearable gear 100 such that the predefined tension is obtainedregardless of the size of the body part.

The strength, the type and the tension force that can be exercised bythe tensioning element 102 such that a predefined tension isautomatically obtained is proportional to the flexibility of thenon-flexible or semi-flexible sleeve 104 of the, or comprised within thewearable gear 100. Such sleeve 104 (preferably bio-compatible) may bemade of, or comprise a polymer, a plastic, such as silicone,polyurethane, a textile, a rubber or other bio-compatible material thatcould be foreseen by the skilled in the art.

Although the holding unit 101 is depicted in FIG. 1 as part of saidnon-flexible or semi-flexible material and positioned opposite to thetensioning element 102 (approximately 180° apart) the skilled in the artwill foresee that said holding unit 101 could also be located anywhereon the wearable gear 100. Among other places, said holding unit 101 canbe collocated with the first end 103 a, or the second end 103 b,alternatively defining an angle of 10°, 20°, 25°, 90° with the centralpoint of the tensioning element 102, or any other angle thereof.

The tensioning element 102 may be shielded (or covered) by a layer of apreferably bio-compatible material such as to increase the subjectcomfort. Said layer may be made of the same material composing orcomprised in the non-flexible or semi-flexible sleeve 104, or made ofanother material.

As an example of the embodiment depicted in FIG. 1 when the wearablegear 100 being worn around a body part (such as the head, a harm, thechest, a leg), the wearable gear 100 will initially expand, partiallybecause of the sleeve 104 (if made of a flexible material), and as aconsequence of the tensioning element 102. When surrounding thesubject's body part, said tensioning element 102 contracts (tensions),consequently pulling the first end 103 a and the second end 103 b suchthat the maximum length is shortened until the predefined tension of thewearable gear 100 is reached (as it will be explained hereunder, saidpredefined tension may corresponds to an absolute value, or a range ofvalues, preferably expressed in Newton (N)). Once said predefinedtension is reached, the tension mechanism stops contracting(tensioning), therefore the predefined tension in the wearable gear 100remains constant, or quasi-constant. As a consequence of said predefinedtension of the wearable gear 100, said wearable gear 100 will exercise apressure on the subject's body part. At a predefined tension, thecorresponding pressure on the subject's body part will preferably be, asit will be further detailed hereunder, between 0.667 kPa (5 mmHg) and6.666 kPa (50 mmHg).

FIG. 2 is a schematic representation of an embodiment of a wearable gear200 according to the present invention, when comprising a physiologicalsensor 207 (such as a pulse oximeter) within the holding unit 201. Thewearable gear 200 further comprises a position indicator 206 (such as avisual indicator). The wearable gear 200 comprises a tensioning element202, a tension mechanism (not shown) and a sleeve 204, said sleevepreferably made of non-flexible or semi-flexible material of the sortdetailed with regard to FIG. 1.

The visual position indicator 206 may be, as depicted in FIG. 2,collocated with the physiological sensor 207, but may also be located atany other locations on the wearable gear 200, for instance next to thephysiological sensor 207, for example within 2 cm, 3 cm, 5 cm or 10 cmon a side of the physiological sensor 207, or at any other location thatcould be foreseen by the skilled in the art. Although depicted as a linewithin FIG. 2, said visual position indicator may be a dot, a square, orany other form that would be foreseen for guiding the subject, or anyother user in positioning properly the wearable gear 200 on the subject,such that the holding unit 201, and consequently the physiologicalsensor 207 are properly positioned on the subject's body part foradequate reading of the physiological parameter, such as vital signs,when in use, by said physiological sensor.

Number of ways are hereby foreseen to provide visual feedback to thesubject or other users via the visual position indicator 206. Thetensioning 202 element may comprise a Velcro or a strap that, whensuperimposed with a portion of the wearable gear 200, a motif isgenerated, such as a line, thereby indicating the physiological sensor207 is properly located on the subject's body part.

Additionally or alternatively, the physiological sensor 207 may becoupled with a deformable element (not shown), such as a gel-filledballoon, or a cushion. Said deformable element being located between thephysiological sensor 207 when within the holding unit 201 and a side ofholding unit 201, or the wearable gear 200 such that said deformableelement deforms when compressed by the physiological sensor on thesubject's body part as a consequence of the increased tension withinsaid wearable gear 200. Said deformable element is configured to providevisual feedback indicative of the tension of the wearable gear 200and/or the pressure applied by the physiological sensor on the subject'sbody part, for instance a change of color when compressed, or a directeddeformation into a certain direction.

Additionally or alternatively, the wearable gear 200 may comprise adisplay (not shown) for indicating the tension within the wearable gear200 and/or the pressure applied by the physiological sensor on thesubject's body part. The display is arranged to receive data (orinformation) outputted by the physiological sensor or any other pressuresensor within or coupled to the wearable gear 200. Additionally oralternatively, the wearable gear 200 is electronically coupleable with adevice comprising a display (such as a mobile phone, a computer, atablet), wherein said device may indicates, or display the tensionwithin the wearable gear 200 and/or the pressure applied by thephysiological sensor on the subject's body part from data (orinformation) outputted by the physiological sensor or any other pressuresensor.

Within the embodiment depicted in FIG. 2, the holding unit 201 comprisesthe physiological sensor 207, such as a pulse oximeter, a reflectivepulse oximeter. Alternatively, said physiological sensor 207 can be ablood pressure sensor, a blood volume sensor, heart rate sensor, atemperature sensor, a respiratory sensor, a galvanic skin responsesensor. The skilled in the art will contemplate that although thewearable gear 200 is depicted comprising a reflective pulse oximeter.The invention is not limited to the foregoing sensors, and the inventionworks similarly with number of other sensors.

The physiological sensor 207 depicted in FIG. 2 is a reflective pulseoximeter comprising two sensor elements, an emitter 207 a and a receiver(or detector) 207 b. Preferably, the emitter 207 a and the receiver 207b are separated from each other by a distance of 3 to 10 mm. Preferablyarranged on a line parallel to the edge of the wearable gear 200, theemitter 207 a and the receiver 207 b may be positioned relative to eachother in any other ways. Alternatively the emitter 207 a and thereceiver 207 b may be collocated such that the physiological sensor 207is made of one sensor element.

The emitter 207 a is configured to emit a light signal such that saidemitted light penetrates the skin barrier of the subject wearing thewearable gear 200, and the detector is configured to receive a lightsignal from the skin barrier of the wearer. Said received light signalcorresponds to the emitted light signal as reflected from the bloodcirculating in blood vessels within the subject's body part, such as theforehead. In other words, reflectance-based pulse oximetry is based onthe principle that emitted light is passed through the skin and isreflected off the subcutaneous tissue and bone before it is detected bya receiver 207 b for further analysis (for instance by a processingunit).

Additionally or alternatively, the wearable gear 200 comprises a wire(or a cable, or a band, or a strap) 105 to connect the physiologicalsensor 207 to a source of energy (such as a battery, a generator),and/or to a processor unit (not shown) which may receive output datacaptured by the physiological sensor 207 when in use. Additionally oralternatively, the wire 105 may enable an electronic connection betweenthe wearable gear 200 and/or the physiological sensor 207 with a mobilephone or a tablet or a computer or any other means that could providesaid wearable gear simultaneously a source of energy and processingcapabilities. Said wire may be connected to the wearable gear 200, orremovely connectable to said wearable gear 200 (such as a USB cable, amicro-USB cable). Alternatively, the source of energy (such as viainduction) and the data transmission could be made wirelessly (such asvia Bluetooth, WIFI, ZigBee), which would alleviate the need of suchwire 105.

The tensioning element 202 is configured to tension the wearable gear200 by a contraction which pulls the first end 202 b and the second end203 b apart from each other such that the maximum length is shorten,thereby creating a pressure on the subject's body part when in use. Theposition indicator helps the installation (the positioning) of thewearable gear 200 such that the physiological sensor 207 is positionedat an appropriate location on the subject′ body part, said appropriatelocation being the one where the sensing signal will be optimal, closeto optimal or sufficient for adequate signal detection and/or signalreading.

The skilled in the art will understand that the tensioning element 202is independent of the positioning of the physiological sensor 207 andwill work similarly even if the position indicator 206 and/or thephysiological sensor 207 is/are not positioned at the appropriatelocation on the subject′ body part.

The tensioning element 202 is configured to cease shortening the maximumlength at a predefined tension of the wearable gear 200 (and/or thesleeve 204) when at least partially around a body part of the subject,said predefined tension corresponding to the pressure value or pressurevalue ranges applied by the physiological sensor 207 on the subject'sbody part. In other words, the tension mechanism is configured toautomatically adjust the maximal length such that the predefined tensionis obtained regardless of the size of the body part.

FIG. 3 is a schematic representation of an alternative embodiment of awearable gear 300 according to the present invention when comprising aphysiological sensor 307 and a position indicator 306. In this exemplaryembodiment, the wearable gear 300 is depicted in use around a body part315, for instance, the head, preferably the forehead. The tensioningelement 303 and the tensioning mechanism (not show) are comprised withinat least a layer of fabric surrounding the wearable gear 300 so as toimprove subject's comfort.

The physiological sensor 307 depicted in FIG. 3 is a reflective pulseoximeter comprising two elements, an emitter 307 a and a receiver (ordetector) 307 b positioned surrounding the body part 315 which isdepicted as the subject's head. The skilled in the art will understandthat said physiological sensor 307 may be of an alternative type, or forgathering alternative measurements, such as, for example a bloodpressure sensor, a blood volume sensor, a temperature sensor, arespiratory sensor, a galvanic skin response sensor an electrocardiogramsensor, a near-infrared spectroscopy sensor, a hemoglobin concentrationsensor, an electro encephalogram sensor, an accelerometer, and anactivity or posture sensor.

Additionally, although the wearable gear 300 depicted in FIG. 3 is aheadband surrounding the subject's head, said headband may be positionedpartially surrounding the subject's head. In a preferred embodiment, theheadband 300 comprises a constant, or nearly constant height throughoutits circumference (i.e. distance between said headband two parallel orsubstantially parallel edges defining a circle or an ellipse around thesubject's head), where said height is preferably between 1 cm and 3 cm.Even more preferably, the height is preferably between 1.5 and 2.5 cm.Alternatively, the wearable gear 300 is a hat, a cap, a bonnet, a hoodor any other wearable garment that can be wear around, partially aroundor on the head of the subject. In alternative embodiments (not shown),the wearable gear is configured to surround or partially surround otherbody parts, for instance the wrist, the arm, the chest or other bodypart of a subject were contact with a physiological sensor 307 at apredefined pressure value or pressure range is needed, advantageous orpreferable.

In the exemplary embodiment depicted in FIG. 3, the tensioning of thetensioning element 303, therefore the wearable gear 300 automaticallyceases when the predefined tension has been reached. Number of meanswill be foreseen by the skilled in the art such that the maximal lengthof the tensioning element 303 is automatically adjusted such that thepredefined tension is obtained regardless of the size of the body part315. For instance, the tension mechanism (not shown) of the wearablegear 300 may be configured to actively or passively cease tensioning ofthe tensioning element 303 when the predefined tension has been reached.

Additionally or alternatively, the wearable gear 300 may comprise ablocking element (not shown) which is configured to cease tensioning ofthe tensioning element 303, alternatively to cease tensioning of thewearable gear 300, once the predefined tension has been reached. Saidblocking element (not shown) can mechanically or electronically preventfurther tensioning of the tensioning element 303 and/or the wearablegear 300. For example, a tensioning mechanism configured not to furtherengage the tensioning element 303 once the predefined pressure isreached, while keeping said predefined tension constant, or nearlyconstant. The tensioning element 303 could be an elastic band or aspring connected to one end of a rigid baseplate and passing through anorifice of the rigid baseplate located at the other end of the rigidbase plate. The blocking element could be an element fixated ontensioning element 303 that cannot pass (is blocked to pass) through theorifice, such that tensioning element 303 is continuously extended. Oncethe external tension of the tensioning element 303 exceeds the tensionof the blocking element, the tensioning element 303 will start to extendwhile keeping the tension within the wearable gear 300.

Additionally or alternatively, said blocking element may compriserotatable knob with built-in slip mechanism. Said slip mechanism isconfigured such that as soon as a certain tension is exceeded on therotatable knob, the rotatable knob starts to internally slip, therebyceasing to apply tension within the wearable gear despites continuingrotation of said rotatable knob. This slip mechanism may for examplecomprises two elements which cooperate with each other until thepredefined tension is reached, and ceasing such cooperation after apredefined threshold is reached. This arrangement provides for a fallsafe scenario which ensure that the wearable gear will not beover-tensioned, therefore ensuring that the pressure exerted by saidwearable gear will not go beyond a certain threshold and simultaneouslyensuring that the tension of the wearable gear will remain within therange values, and/or ensuring that the pressure exerted by said wearablegear (or by the physiological sensor) on the subject's body remainswithin the preferred range of value.

Additionally or alternatively, an example of an electrical means forsuch blocking element (not shown) may include a motor (for instance alinear electromotor based on piezo electric principle) configured tostop tensioning the tensioning element 303 when the predefined pressureis reach as measured, detected or estimated for instance, via a pressuresensor. Said embodiment will be further detailed by means of FIG. 11.

As a safeguard mechanism, such as to avoid overpressure for instance,the first end of the wearable gear 303 a and the second end of wearablegear 303 b (alternatively the first end and the second end of thetensioning element) may each comprise a magnetic connector (e.g. eachend comprising a magnet of opposite polarity) such that once connected,the wearable gear surrounds the body part 315 of the subject. Themagnetic dipole-dipole interaction between the magnets must be such thatonce the predefined tension is reached, the two magnets separate fromeach other. To achieve the foregoing, the vector component of themagnetic force between the magnets should be no more than equal and inthe same direction to the vector component of the tension in thewearable gear 300 when the predefined tension is reached. Consequently,at a tension superior to the predefined tension, the magnetic force willnot be strong enough to keep the magnets coupled to each other, therebyprovoking a separation thereof. This safeguard is especially useful whenthe wearable gear further comprises a manual adjustment unit (such as astrap or a wheel for incremental adjustment of the tension in thewearable gear), thereby for incremental adjustment of the pressureapplied by the physiological sensor on the body part 315 of the subject.

Additionally or alternatively, the wearable gear further comprises apressure sensor 316 for measuring, or determining, or detecting, orestimating the pressure applied to by the physiological sensor 307 onthe subject's body part 315, and for outputting a pressure signalindicative of said measured, or determined, or detected, or estimatedpressure. The outputted pressure signal may be used by a display (notshown) (as further elucidated hereunder), or by a motor (not shown)coupled to the tension mechanism 303 such that the maximal length isautomatically adjusted based on the said sensor signal such that thepredefined tension is obtained regardless of the size of the body part315.

FIG. 4 is a graphical representation of the tangential force (in Newton(N)) in a wearable gear 400 relative to the circumference (in centimeter(cm)) of the body part. The predefined tension (so called “tangentialforce in the headband” in FIG. 4) depicts the preferred tension rangedepending on the body part circumference such that a predefined pressurerange is applied on said body part. Within a wearable gear of the kindaccording to the present invention, the tangential force applied on thewearable gear on the body part is calculated by Laplace's law whichreads:

Force(N)=((Contact Pressure)×(Circumference)/2π)×(Height)

Where (Force) is the tangential force in the wearable gear, (contactpressure) is the force (in N) applied by the wearable gear onto the bodypart surrounded by the wearable gear, (circumference) is thecircumference of the body part and height is the average verticaldistance between two parallel or substantially parallel edges of thewearable gear in contact with the body part, said vertical distancemeasured perpendicularly between two parallel lines, or nearly parallellines defining the two edges of the wearable gear to surround the bodypart.

The graphical representation of FIG. 4 demonstrates the preferentialtension ranges for a given circumference, therefore the so-calledpredefined tension. As elucidated herein, the tension mechanismaccording to the present invention is optimized to tension thetensioning element such that the predefined tension is reached, saidpredefined tension being preferably within the range of valuesrepresented in FIG. 4, where some examples are extracted and representedin table 1 hereunder.

TABLE 1 Body Part Predefined tension range Predefined tension range forcircumference per unit band height a headband of height 2 cm (in cm) (inN/cm) (N) 20 0.64-1.06 1.27-2.12 25 0.80-1.33 1.59-2.65 30 0.95-1.591.90-3.18 35 1.11-1.86 2.22-3.71 40 1.27-2.12 2.54-4.24 45 1.43-2.392.86-4.77 50 1.59-2.65 3.18-5.30 55 1.75-2.92 3.50-5.83 60 1.91-3.183.81-6.36 65 2.07-3.45 4.13-6.89

FIG. 5 is a schematic representation of a tensioning element 502 coupledto a tension mechanism 545 according to an embodiment of the presentinvention, said tensioning mechanism 545 configured to tension thetensioning element 502 to a predefined tension when at least partiallyaround a body part of the subject. In said embodiment, the tensioningelement 502 is depicted with a tension mechanism 545 comprising a firstpart 550 a comprising non-resilient material, for instance fabric, saidfirst part being further coupled, or alternatively part of, the wearablegear (not shown). The tension mechanism 545 further comprises a secondpart 570 comprising resilient material, for instance an elastic (forinstance, a rubber, a polymer), a spring, preferably a clock spring or apower spring. The second part 570 is coupled to a rotating element (forinstance, a rotating drum) 575, said rotating element is configured tomechanically cooperate with the tensioning element 502 coupled orconnected to an end of the first part 550 b or alternatively to anon-resilient part of the wearable gear. Additionally or alternatively,the rotating element 575 (such as a drum) comprises a central axis 560so as to enable rotation thereof.

As depicted in FIG. 5, the mechanical cooperation between the secondpart 570 and the tensioning element 502 is such that the distancebetween the two ends of the first part 550 a, 550 b are movable relativeto each other such that their relative distance may be altered as aresult of said mechanical cooperation. For example, when the second part560 comprises a spring, it will be understood by the skilled in the artthat compression of the spring will pull the tensioning element 502towards the central axis 560 thereby reducing the distance between thetwo ends of the first part 550 a, 550 b, and extension of the springwill push the tensioning element 502 away from the central axis 560thereby increasing the distance between the two ends of the first part550 a, 550 b.

In an exemplary embodiment, the tensioning element 502 is a wire (forinstance a metal wire, a plastic wire, a nylon wire, a Kevlar wire), aband, a strap which is coupled or connected to the clock spring 570 sothat upon tensioning, the clock spring 570 pulls the wire 502 which mayroll around or partially around the rotating drum rotating around itscentral axis 560. As the wire 502 is coupled of connected to a part ofthe wearable gear 550 b, the circumference of said wearable gear isconsequently diminished. In use, when the wearable gear surrounds orpartially surrounds a body part, said body part being lightlycompressible, or alternatively incompressible, the diminution of thewearable gear circumference increases the tension of said wearable gear,and consequently increases the pressure exerted by said wearable gear onthe body part. The skilled in the art will understand that theincreasing of tension, and therefore the increasing of pressure inaccordance with this exemplary embodiment may apply to all embodimentsof the present invention.

Alternatively, the warble gear (not shown) may comprise more than onetension mechanisms which cooperate with each other, for instance twotension mechanisms attached to two ends of the warble gear, at leastsaid two ends comprising, or made of non-resilient material. As hereindepicted, the tensioning element 502 is at one end coupled to a rotatingelement 570 attached to the first end of the first part 550 a, and theother end of said tensioning element 502 is coupled (or attached) to thesecond end of the first part 550 b. Similarly, the second tensionmechanism comprises a second tensioning element 502 coupled at one endto a rotating element attached to the second end of the first part 550b, and at the other end to the end of the first part 550 a. By thisarrangement, the wearable gear containing a tensioning element 502comprising two tension mechanisms will be understood as being morerobust than a wearable gear with only one tension mechanism 545;although substantively all other aspects of the present invention arereach in the same or in a similar manner such that the tension mechanism545 is configured to automatically adjust the maximal length such thatthe predefined tension is obtained regardless of the size of the bodypart.

It will be understood by the skilled in the art that the spring 570 andthe first end of the wearable gear 550 mechanically cooperate with eachother to automatically adjust the length of the wire 502, therebymodifying the tension within the wearable gear and further configuredsuch that the predefined tension is obtained regardless of the size ofthe body part.

FIG. 6 is a schematic representation of a tensioning element 602 coupledto a tension mechanism 645 according to an embodiment of the presentinvention. The tension mechanism 645 is configured for tensioning thetensioning element 602 to a predefined tension when at least partiallyaround a body part of the subject. This embodiment is an alternative tothe embodiment depicted in FIG. 5, and works substantially according tothe same principles.

The tensioning element 602 comprises a tension mechanism 645 comprisinga first part comprising non-resilient material 650, and a second partcomprising resilient material 670. By means of example, thenon-resilient material 650 consists of a casing (enclosing shell, tube,or surrounding material) for hosting, alternatively partially hosting,the resilient material 670, for instance a spring, for instance a clockspring, for instance a power spring, wherein said casing is coupled, orconnected to an part or a section of the wearable gear such that in use,a reduction of the maximal length provokes a reduction of thecircumference of the wearable gear, thereby generating an increasedtension therein. The tension mechanism 645 further comprises a rotatingelement 660 (for instance, a rotating drum), wherein said rotatingelement 660 is preferably configured such that the resilient material670 may rotatably surrounds said rotating element 660. Additionally, thetensioning element 602 comprises a band, or a wire, or a strap connectedto the rotating element 660 such that upon tensioning of the tensioningelement 602 (e.g. a band), the band 602 is pulled-in the rotatingelement 660, and upon extending of the tensioning element 602, the band602 is pulled-out the rotating element 660. Said band 602 is coupled,alternatively connected, with a second part of the wearable gear 650 bsuch that a diminution or an extension of the maximum length directlyinfluences to size (or circumference) of the wearable gear, therebymodifying the tension therein, and consequently the pressure exertedthereof on the body part when in use.

Alternatively or additionally, the wearable gear (not shown) maycomprise more than one tension mechanisms which cooperate with eachother, for instance two tension mechanisms attached to two ends of thewearable gear, at least said two ends comprising, or made ofnon-resilient material. As depicted herein, the tensioning element 602is at one end coupled to a rotating element 670 within or partiallywithin a casing. Similarly, a second tension mechanism comprises asecond tensioning element 602 coupled at one end to a rotating element660 within or partially within a casing. Said tensioning element 602,for instance a band is attached, or coupled, at both ends respectivelyto both tension mechanisms. By this arrangement, the wearable gearcontaining a tensioning element 602 comprising two tension mechanismswill be understood as being more robust than a wearable gear with onlyone tension mechanism 645; although substantively all other aspects ofthe present invention are reach in the same or in a similar manner suchthat the tension mechanism 645 is configured to automatically adjust themaximal length such that the predefined tension is obtained regardlessof the size of the body part.

It will be understood by the skilled in the art that the spring 670 andthe first end of the wearable gear 650 mechanically cooperate with eachother to automatically adjust the length of the band 602, therebymodifying the tension within the wearable gear and further configuredsuch that the predefined tension is obtained regardless of the size ofthe body part.

FIG. 7 is a schematic representation of a tensioning element 702 coupledto a tension mechanism 745 according to an embodiment of the presentinvention. The tension mechanism 745 is configured for tensioning thetensioning element 702 to a predefined tension when at least partiallyaround a body part of the subject. This embodiment is an alternative tothe embodiments depicted in FIG. 5 and FIG. 6, and works substantiallyaccording to the same principles.

The tensioning element 702 comprises a first part comprising a resilientmaterial 770 (for instance a spring, for instance a clock spring, forinstance a power spring) coupled to a second part 750, such as a casing(enclosing shell, tube, or surrounding material) to host the resilientmaterial 770, wherein said casing is coupled, or connected to an part(or a section) of the wearable gear such that in use, a reduction of themaximal length provokes a reduction of the circumference of the wearablegear, thereby generating an increased tension therein, and consequentlythe pressure exerted thereof on the body part when in use. In thisexample, the tension mechanism comprises a first rotating element 760(such a first drum) fixably connected to the casing 750 and coupled to asecond rotating element 775 (such as a second drum). The tensioningmechanism further comprises a tensioning element 702 such as band, or awire, or a strap coupled to the resilient material 770 such that saidresilient material 770 may, when compressed, pulled-in the band 702within the casing such that it surrounds (at least partially) the firstrotating element 760, and is surrounded (at least partially) by thesecond rotating element 760. Said band 702 is coupled (alternativelyconnected) with a second part of the wearable gear 750 b such that adiminution or an extension of the maximum length directly influences tosize (or circumference) of the wearable gear, thereby modifying thetension therein.

Alternatively or additionally, the wearable gear (not shown) maycomprise more than one tension mechanisms which cooperate with eachother, for instance two tension mechanisms attached to two ends of thewearable gear, at least said two ends comprising, or made ofnon-resilient material. As depicted herein, the tensioning element 702is at one end coupled to a rotating element 770 within or partiallywithin a casing. Similarly, a second tension mechanism comprising asecond tensioning element 702 is coupled at one end to a rotatingelement 770 within or partially within the casing. Said tensioningelement (e.g. the band) 702 is attached (or coupled) at both endsrespectively to both tension mechanisms. By this arrangement, thewearable gear containing a tensioning element 702 comprising two tensionmechanisms will be understood as being more robust than a wearable gearwith only one tension mechanism 745; although substantively all otheraspects of the present invention are reach in the same or in a similarmanner such that the tension mechanism 745 is configured toautomatically adjust the maximal length such that the predefined tensionis obtained regardless of the size of the body part.

It will be understood by the skilled in the art that the spring 770 andthe first end of the wearable gear 750 mechanically cooperate with eachother to automatically adjust the length of the band 702, therebymodifying the tension within the wearable gear and further configuredsuch that the predefined tension is obtained regardless of the size ofthe body part.

FIG. 8 is a schematic representation of a tensioning element 802 coupledto a tension mechanism 845 according to an embodiment of the presentinvention. The tension mechanism 845 is configured for tensioning thetensioning element 802 to a predefined tension when at least partiallyaround a body part of the subject.

The tensioning mechanism 845 comprises a first part comprising aresilient material 870, for instance a circular spring or a clock springof a power spring, and a second part comprising non-resilient material850, for instance laces. This arrangement enables the circular spring toroll up the laces, thereby exerting a tension within the wearable gear,and consequently a pressure on the body part. By having laces on bothsides of the circular spring, the invention can enable contraction onboth sides of the spring, thereby enabling twice the range ofcontraction possible by means of a single spring.

FIG. 9 is a schematic representation of a tensioning element 902 coupledto a tension mechanism 945 according to an embodiment of the presentinvention The tension mechanism 945 is configured for tensioning thetensioning element 902 to a predefined tension when at least partiallyaround a body part of the subject.

The tension mechanism 902 comprises a first part comprising a resilientmaterial 970, for instance a spring, a clock spring, a power spring, ahelical torsion spring, a constant-force spring, or a rubber-band motor,and a second part comprising non-resilient material 950, preferably afirst end of the wearable gear. The spring 970 is coupled, oralternatively connected, to a first end of a tensioning element 902 (forinstance a wire, a metal wire, a plastic wire, a nylon wire, a Kevlarwire), a band, a strap, wherein a part of said wire 902 is coupled to asecond end of the wearable gear, and wherein the second end of said wire902 is connected to the first end of the wearable gear 950 a. In otherwords, the wire 902 has its first and second ends on one end of thewearable gear 950 a and is coupled between these two ends to the secondend of the wearable gear 950 b such that an open loop is formed.

It will be understood by the skilled in the art that the spring 970 andthe first end of the wearable gear 950 mechanically cooperate with eachother to automatically adjust the length of the wire 902, therebymodifying the tension within the wearable gear and further configuredsuch that the predefined tension is obtained regardless of the size ofthe body part.

FIG. 10 is a schematic representation of a tensioning element 1002coupled to a tension mechanism 1045 according to an embodiment of thepresent invention. The tension mechanism 1045 is configured fortensioning the tensioning element 1002 to a predefined tension when atleast partially around a body part of the subject.

The tension mechanism comprises a first part of a resilient material1065 made of a polyamide, or polyurethane or silicone which is shapedsuch as to depict a zigzagged geometry. The zigzagged geometry basicallyacts as a spring, and may comprise polyurethane material, or be apolyurethane spring. The advantage of such a geometry is that thewearable gear can be made out of one piece of material, without anyjoints or connections. The whole wearable gear, such as tan headband canbe made out of one material.

Alternatively, the tension mechanism comprises a first part comprising aresilient material 1065, such as a sliding part, and a second part ofnon-resilient material 1060, such as a lever or a combination of a leverand an elastic material or spring. The first and the second part areconfigured to cooperate with each other such that when the sliding partand the lever are engaged, the lever may be pushed to a closed statewhich adds a defined amount of tension within the wearable gear, therebyreaching automatically the predefined tension.

FIG. 11 is a schematic representation of a tensioning element 1102coupled to a tension mechanism 1145 according to an embodiment of thepresent invention. The tension mechanism 1145 is configured fortensioning the tensioning element 1102 to a predefined tension when atleast partially around a body part of the subject.

The tension mechanism 1145 comprises a first part comprising a resilientmaterial 1170, for instance a torsion spring, and a second partcomprising a non-resilient material 1150, preferably a first end of thewearable gear. The spring 1170 is coupled, or alternatively connected,to a first end of a band 1165 (for instance a metal wire, a plasticwire, a nylon wire, a Kevlar wire), a strap, wherein a part of said band1165 is coupled to a second end of the wearable gear, and wherein thesecond end of said band 1165 is connected to the first end of thewearable gear 1150.

The tension mechanism 1145 is coupled to a motor 1180, preferably anelectro-motor configured to rotate the spring 1170, for instance by arotating element 1160, such that a tensioning element 1102 such as aband may go within said rotating element thereby, when said band 1102 isconnected or coupled to a second end of the wearable gear, shortening orincreasing the total length so that the tension is respectivelyincreased or decreased. The motor 1180 is configured to stop when thepredefined pressure is adjusted based on a sensor signal, as explainedearlier, said signal being outputted either from a pressure signal orfrom the physiological sensor and received by the motor 1180, or by aprocessing unit or control unit (not shown) coupled to said motor 1180.

It will be understood by the skilled in the art that the spring 1170 andthe first end of the wearable gear 1150 mechanically cooperate with eachother to automatically adjust the length of the band 1165 as aconsequence of the motor 1180, thereby modifying the tension within thewearable gear and further configured such that the predefined tension isobtained regardless of the size of the body part.

FIG. 12 is a schematic representation of a method according to thepresent invention. The method for holding a physiological sensor formonitoring a subject, said method comprising the steps of providing awearable gear comprising a tensioning element having a maximal length(S1).

Additionally, the method comprises the step of coupling to the wearablegear to a holding unit for holding the physiological sensor (S2).

Additionally, the method comprises providing a tension mechanism fortensioning the tensioning element to a predefined tension when at leastpartially around a body part of the subject (S3).

Additionally, the method comprises providing the tension mechanism whichis configured to automatically adjust the maximal length such that thepredefined tension is obtained regardless of the size of the body part(S4).

Although the method is hereby depicted as comprising four main steps,the present invention additionally or alternatively foresee additionalsteps, or sub-steps in accordance with any embodiments of the wearablegear, or the monitoring device according to the present invention. Themethod is in no means limited to these four steps, and fulfill similaror analogous advantages as the wearable gear, or the monitoring deviceaccording to the present invention.

While the invention has been illustrated and described in detail in thedrawings and foregoing description, such illustration and descriptionare to be considered illustrative or exemplary and not restrictive; theinvention is not limited to the disclosed embodiments. Other variationsto the disclosed embodiments can be understood and effected by thoseskilled in the art in practicing the claimed invention, from a study ofthe drawings, the disclosure, and the appended claims. In the claims,the word “comprising” does not exclude other elements or steps, and theindefinite article “a” or “an” does not exclude a plurality. The merefact that certain measures are recited in mutually different dependentclaims does not indicate that a combination of these measures cannot beused to advantage.

1. A wearable gear for holding a physiological sensor for monitoring asubject, the wearable gear comprising: a tensioning element having amaximal length; and a holding unit for holding the physiological sensor;characterized in that: the wearable gear further comprises a tensionmechanism for tensioning the tensioning element to a predefined tensionwhen at least partially around a body part of the subject, wherein thetension mechanism comprises a resilient part comprising a resilientmaterial and a non-resilient part comprising a non-resilient material;and wherein the resilient part and the non-resilient part mechanicallycooperate with each other to automatically adjust the maximal lengthsuch that the predefined tension is obtained regardless of the size ofthe body part.
 2. The wearable gear as claimed in claim 1, wherein theresilient part comprises a spring or an elastic.
 3. The wearable gear asclaimed in claim 2, when comprising a spring, wherein the spring is oneof a torsion springs, a helical torsion spring or a clock spring.
 4. Thewearable gear as claimed in claim 1, wherein the maximal lengthcomprises: a first portion; a second portion; wherein said first portionand second portion are coupleable by a coupling element, said couplingelement configured to connect said first portion and said second portionsuch that the coupling element enables the first portion and the secondportion to move relative to each other such that the predefined tensionremains stable when surrounding the body part once the predefinedtension is reached.
 5. The wearable gear as claimed in claim 4, whereinthe coupling element is further configured to enable the wearable gearto be held in place when at least partially surrounding the body partwhen the first portion and second portion are coupled to each other. 6.The wearable gear as claimed in claim 1, wherein the wearable gearfurther comprises a position indicator for indicating the appropriateplacement of the wearable gear or the holding unit on or at leastpartially around the subject's body part.
 7. The wearable gear asclaimed in claim 1, wherein the coupling element and the tensionmechanism are congruent.
 8. (canceled)
 9. The wearable gear as claimedin claim 1, wherein the predefined tension enables a pressure rangebetween 0.667 kPa (5 mmHg) and 6.666 kPa (50 mmHg), preferably between2.000 kPa (15 mmHg) and 3.333 kPa (25 mmHg) applied on the body part.10. The wearable gear as claimed in claim 1, wherein the wearable gearis a headband to be worn at least partially around a head of thesubject.
 11. A monitoring device for monitoring a vital sign of asubject, the monitoring device comprising: a tensioning element amaximal length; and a physiological sensor for receiving vital signparameter data; characterized in that: the monitoring device furthercomprises a tension mechanism for tensioning the tensioning element to apredefined tension when at least partially around a body part of thesubject, wherein the tension mechanism comprises a resilient partcomprising a resilient material and a non-resilient part comprising anon-resilient material; and wherein the resilient part and thenon-resilient part mechanically cooperate with each other toautomatically adjust the maximal length such that the predefined tensionis obtained regardless of the size of the body part.
 12. The monitoringdevice as claimed in claim 11, wherein the physiological sensor is apulse oximeter, preferably a reflective pulse oximeter.
 13. Themonitoring device as claimed in claim 11, wherein the physiologicalsensor is coupled to a pressure sensor, said pressure sensor configuredto generate a pressure signal indicative of the pressure exercised bythe physiological sensor on the body part.
 14. The monitoring device asclaimed in claim 11, wherein the tension mechanism is configured tocease tensioning of the monitoring device when the pressure sensorreaches a predefined threshold indicative of the predefined pressure orpressure range.
 15. The monitoring device as claimed in claim 11,further comprising a feedback unit for providing a feedback as to thepositioning of the physiological sensor relative to a position ofinterest of the subject.
 16. A method for holding a physiological sensorfor monitoring a subject, said method comprising the steps of: providinga wearable gear comprising a tensioning element having a maximal length;coupling to the wearable gear to a holding unit for holding thephysiological sensor; characterized in providing a tension mechanism fortensioning the tensioning element to a predefined tension when at leastpartially around a body part of the subject, wherein the tensionmechanism comprises a resilient part comprising a resilient material anda non-resilient part comprising a non-resilient material; providing theresilient part and the non-resilient part to mechanically cooperate witheach other to automatically adjust the maximal length such that thepredefined tension is obtained regardless of the size of the body part.